Which Is True of the Amount of CO2 in Our

Multiple Choice

Which is true of the amount of CO2 in our atmosphere?

A) CO2 is the most abundant gas in the atmosphere.
B) The level of CO2 has been decreasing at the rate of 3.1% per year since 2000.
C) The level of CO2 increased at the rate of 1.1% per year from 1990 to 1999.
D) The level of CO2 has been much higher during the past 800,000 years than it is now.